Car should have had an intermediate service every 16,000km and a full service every 32,000km - check the cars service book for a Lexus service history.
Pads and disks should still be Ok after 65,000km 'normal' driving. Belts usually need replacing after 100,000km.
Also, €15,000 is very good value for a '99 IS200 with 40,000 miles on the clock but I would still have the car checked out if you're buying it privately
P.S. what do people think of Lexus in Italy?